Method of manufacturing laminated metal bands



Patented Dec. 25, 1934' MANoFAoTUnInG LAMINATED .METAL BANDS i fMETHoi) or Franz Jordan, Berlin-Charlottenburg; Germany No- Dra wing. Application December a, 1932,

- Serial 1932 i The quality of the projection of cinematographic pictures by reflected light instead ofby light passing directly through a translucent film depends not onlyupon the 'clearness of'the pic- .5 tures and the strength of. the light; but also on theireflecting. surface employed.

It has been found by experiment that aluminium, on account of its white metallic lustre, is excellent as a reflecting surface. This appears all the more favorable inasmuch as the light weight of aluminium brings it clearer to the usual very light cellulose 'film. Nevertheless, it has been already found that a film strip of aluminium as light in weight as a cellulose film and correspondingly thinner than the latter does not stand up well in use. It has, therefore, been proposed to use a steel strip or band having an aluminium coating instead of a cellulose film. Every form of aluminium coating or covering is, however, not suitable for the purpose, due to optical requirements.

Now, according to the present invention, for the purpose of applying the aluminium coating or covering so that it will have the brightest lustre and light-reflecting power and be free from spots and blemishes, a magnetic iron core is taken and also an aluminium covering for each side thereof, and the whole passed in heated statethrough between pressure rollers which are smooth, clean and have a lustrous polish, the pressure of the core and its coverings continuing until a film band thinness approximately from 0.03 to 0.05 of a millimeter is attained.

It has been found that by alloying aluminium with precious metals, for example silver, the lustre and light-reflecting power of the aluminium covering is increased, and as a further feature of my invention such an alloy may be employed to form the coverings for the iron core referred to.

With the small thickness of the aluminium iron-cored film band, about from 0.03 to 0.05 of a millimeter, the coverings themselves must, of course, be correspondingly thin, some thousandths of a millimeter. As the plating and roll- .ing process from the thicker iron and coverings No.,648,6 45. ,In Germany November 6,

4 onne (o1. 29 -139) of the band, the latter being, thus, non-inflammable and rustless. These precautions being observed, there is no diificulty in rolling out the aluminium coverings to the thickness above mentioned, as the aluminium by the roller-process is smoothly applied and slipping between the rollers is prevented. The rolling pressure can be higher than with iron alone, as the latter at high pressure easily slips and tears. The band, as a whole, is lowered in weight as a result of its covering with the aluminium so that its excess of weight over the other bands, such as those of celluloid and other materials, is only trifling.

Further, the band according to this invention has strong magnetic properties so that it is very suitable for use with magnetic tone films. Both the picture and the sound in a tone film can, therefore, be photographed together, exactly as in celluloid films. Still further, the band of this invention is valuable for the projection of colored films, as through the indirect projection over the metallic covering of the band the colors appear clear and unaltered. This is never the case with even a fully clear film band through which light is projected, as in such conditions the colors do not come out exactly true upon the screen. It will be understood that the metal band may have printed thereon in black or in colors any notices or textual additions, and these may be projectable.

Not only does the band made according to this invention show all advantages possessed by hitherto proposed film bands, but it adds the advantage that it is fireproof and will not alter when kept in store which is not the case with known celluloid film bands. The new band is also weldable; this increases its utility as a plurality of such bands may be electrically welded together at their ends. The cost of production is lower than that of most known formsof film bands.

1. A mode of carrying out the method for manufacturing laminated metal bands suited as carriers for speaking films and comprising unwinding from individual spools an iron band serving as core in the laminated band to be made, and two aluminium bands serving as coverings for said core, heating the three bands, and uniting them with one another by welding them together in hot state between pressing rollers, said mode comprising employing for the coverings an alloy of aluminium and a small addition of a precious metal having a white lustre, and transforming the laminated band into foils of a thickness of from 0.03 to 0.05 mm between polished rollers of a polishing mill.

2. A mode of carrying out the method for manufacturing laminated metal bands suited as carriers for speaking films and comprising, unwinding from individual spools an iron band serving as core in the laminated band to be made, and two aluminium bands serving as coverings for said core/heating the three bands and uniting them with one another by welding them together in hot state between pressing rollers, said mode comprising employing for the coverings analloy of aluminum and a small addition of a precious metal having a white lustre and being adaptedto prevent the color of the aluminium from changing as otherwise caused by the diffusion between the aluminium and the iron i'n'hot state; and transforming the laminated band into foils of a thickness of from 0.03 to 0.05 mm between highly polished rollers of a polishing mill.

3. A mode of carrying out the method formanufacturing laminated metal bands suited as carriers for speaking films and comprising, unwinding from individual spools an iron band serving as core in the laminated band to be made, and two aluminium bands serving as coverings for said core, heating the three bands and uniting them with one another by welding them together in hot state between pressing rollers, said mode comprising employing for the coverings an alloy of aluminium and a small addition of silver; and transforming the laminated band into foils of a thickness of from 0.03 to 0.05 mm between polished rollers of a polishing mill.

4. A mode of carrying out the method for manof aluminium and a small addition of a precious metal having a white luster; transforming the laminated band into foils of a thickness of from 0.03 to 0.05 mm between polished rollers of a polishing mill, overlapping mutually the ends of the thus manufactured laminated band, and uniting them by electric welding.

FRANZ JORDAN. 

